5. Liv Tyler And Alicia Silverstone In Crazy - Aerosmith
Alicia Silverstone was already a name when she appeared in Aerosmith's Crazy - in fact, it was her third appearance in an Aerosmith video - while Liv Tyler was making her debut (she'd been spotted in commercials). Tyler, who for much of her life wasn't even aware she was the daughter of lead singer Steven Tyler, actually hit it big thanks to the appearance and would go on to roles in Armageddon and The Lord of the Rings.